Patent JPH0898321A successfully refreshed from Google Patents.
Patent US2996390A successfully refreshed from Google Patents.
US2996390A
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Optical glass with anomalous partial dispersion
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1953-11-13
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Granted: 1961-08-15
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Expires: 1973-11-13
Abstract
No abstract record available.
Inventors
- 👤 Weissenberg Gustav
- 👤 Meinert Norbert
- 👤 Marburg Kreis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:57
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/12; C03C3/16; C03C3/19; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/901; Y10S501/903
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
SUBSTANTIALLY FLUORINE FREE FLINT GLASS WITH LOW INDEX OF REFRACTION AND HIGH DISPERSION CONSISTING ESSENTIALLY OF A MELT OF A MIXTURE OF A METAPHOSPHATE OF AN ALKALINE EARTH METAL, AN ALKALI CARBONATE AND TITANIUM OXIDE SAID TITANIUM OXIDE COMPRISING FROM 2.7% TO 14.3% BY WEIGHT OF THE MELT AND THE METAPHOSPHATE COMPRISING FROM 47.6% TO 54% BY WEIGHT OF THE MELT.
Claim 2
Dependent Claim
61 words
SUBSTANTIALLY FLUORINE FREE FLINT GLASS WITH LOW INDEX OF REFRACTION AND HIGH DISPERSION CONSISTING ESSENTIALLY OF A MELT OF A MIXTURE OF A METAPHOSPHATE OF AN ALKALINE EARTH METAL, AN ALKALI CARBONATE AND TITANIUM OXIDE SAID TITANIUM OXIDE COMPRISING FROM 2.7% TO 14.3% BY WEIGHT OF THE MELT AND THE METAPHOSPHATE COMPRISING FROM 47.6% TO 54% BY WEIGHT OF THE MELT.
References Cited (Backward Citations)
US2684304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-14 | 1965-02-13 | 1965-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-14 | 1969-02-13 | 1969-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-14 | 1973-02-13 | 1973-08-15 | $7700.00 | Window Closed / Lapsed |